main {
  height: 300px;
  display: flex;
  section {
    flex: 1;
    &:nth-child(1) {
      background-color: darkseagreen;
      margin-right: 5px;
    }
    &:nth-child(2) {
      display: flex;
      flex-flow: column;
      & > div {
        flex: 1;
        background-color: burlywood;
        &:nth-child(2) {
          background-color: cornflowerblue;
          margin-top: 5px;
        }
      }
    }
  }
}
